The Mobile Secure Gateway (MSG) is a term that is used for software or hardware appliance that gives secure communication between a mobile application and the respective back end source generally within the boundary of the organization network. It points the challenges in the fields of mobile security. Generally Mobile Secure Gateway contains two components, they are, Client Library and Gateway. The client is a library that is connected with the mobile application. It establishes secure connection with Gateway with the help of crystallographic protocol generally TLS/SSL. This gives a secured channel used for communication between the hosts and mobile application. Whereas, Gateway separates internal IT infrastructure from the internet thus enabling only an authorized client requests to approach and especial collection of hosts inside a restricted network. 
The client library is connected with the respective mobile application which gives secure access through the Gateway of collection of Hosts. The Client library shows public API to mobile application copying the HTTP client library that is platform default. The application uses this API to communicate with wanted hosts in a secured manner. Gateway is a daemon or server generally installed in virtual or physical appliance that is placed in DMZ. The Gateway public interface is made visible to the internet or other network which are not trusted and it accepts IP/TCP connections from mobile applications. It operates on IPv4 and IPv6 network models. The incoming client connects generally using TLS/SSL in order to give security for the network communication and a common trust of communication friends. The communication protocol is generally based on HTTP or SPEEDY. The gateway transmits requests from apps connected to a set of hosts configured. Generally, these ate HTTP or HTTPS services or servers within an internal network. The response from a host is transmitted back to the respective communication app.